The present invention relates to in-line or so-called tandem roller skates and comprises a faster and more smoothly operating in-line roller skate, which is easily manufactured and more durable under both normal and extreme operating conditions. The present invention has a particular advantage for those users seeking to have all the movement options available normally only to the users of ice skates.
In-line roller skates typically utilize two or more wheels positioned to rotate within a common, vertical plane and while operating as roller skates have much of the feel and behavior associated with ice skates. Substantially the same body movements are required to operate both ice and in-line roller skates, and such roller skates have become increasingly popular with ice skaters as a desirable training tool for off season and on-street use. In recent years, they have been capturing an increasing share of the recreational skate market and in time may parallel jogging as a healthy and pleasurable adult sport.
It is desirable therefore to have an in-line skate capable of all the same movements as a regular ice skate, preferably by using the same movements of the body so that a single user can seamlessly switch between the ice skate and the in-line skate.
In-line skates are well known and appear at least as early as 1876 in the U.S. Pat. No. 7,345 of C. W. Saladee, which disclosed a two-wheel in-line model featuring a somewhat complex, spring loaded carriage supporting laterally pivoting rollers for improved maneuverability and even distribution of skater weight but was heavy, noisy and quite complicated to manufacture and assemble.
In 1946, the U.S. Pat. No. 2,412,290 to Rieske disclosed a heavy metal framed, three-wheel, in-line skate for indoor use which featured an endless, rubberized belt so as to avoid damage to wooden floors. The belt rotated on three pulley-like wheels wherein the intermediate wheel was vertically adjustable to produce a rocking action in a forward or rearward direction, which made it easier to steer and maneuver the skate. Vertical adjustment of the intermediate wheel was achieved by a clamping bolt and a system of interlocking teeth and allowed a range of vertical adjustment.
In 1966, G. K. Ware in the U.S. Pat. No. 3,287,023 disclosed an in-line skate with thin, rounded wheels, which endeavored to simulate the performance of ice skates. The Ware skate utilized a fairly heavy metal frame having front and rear frame members with longitudinally extending and overlapping sections. Three sections had a multiplicity of horizontally arranged axle apertures which permitted positioning of wheel axles in a variety of different locations and provided continuous adjustability of the frame to accommodate a wide variety of boot sizes. The Ware frame also included the positioning of apertures at several elevations at the front and rear of the skate so that the forward and rear wheels could be at a higher level than the two intermediate wheels. The Ware frame and variations of it are still in use on currently available in-line roller skates and has been the best all around frame available for such skates.
The U.S. Pat. No. 4,492,385 to Olson disclosed a hybrid skate combining the desirable features of both ice and roller skates and featured a mounting system which could carry either the traditional ice skating blade or a series of in-line wheels.
Other in-line roller skates with various wheel structures and configurations are shown in U.S. Pat. Nos. 3,880,441, 3,900,203, 3,963,252, and 4,618,158. A number of distinct wheel structures have been developed for use with in-line skates, conventional roller skates and other roller devices, some of which are shown in U.S. Pat. Nos. 189,783, 2,670,242, 4,054,335 and 4,114,952 incorporated herein by reference.
The use of one or multiple ball supports on one or both ends of the in-line skate is known from a number of patents. U.S. Pat. No. 862,431 by Armband shows an in-line skate with a ball at the rear end of the skate. Blankenburg also shows several balls incorporated into the design of his skate as shown in the U.S. Pat. No. 5,207,454. The general concept is to increase the ability of the user to do turns in a similar way as the ice skaters do.
Although most of the designs of in-line roller skates incorporate the string of rollers positioned along a straight line for improved stability, some designs attempt to mimic the curved design of some ice skates and position the rollers along a curved line. For example, the U.S. Pat. No. 5,964,469 by Grossman shows one such design where at least two front wheels and two rear wheels are suspended at a point higher than the main string of rollers. Stein in the U.S. Pat. No. 1,988,055 describes a similar concept so as Madsen in the U.S. Pat. No. 1,260,692. Some of these patents also describe the use of rollers of different diameters to accommodate the curvature of the skate.
Despite many attempts to create an in-line skate with all the same characteristics as the ice skate, such design has never been achieved. The need therefore still exists for an in-line skate allowing the user to perform substantially all the same movements as with the ice skate. The need also exists for such a skate to have a simple and easily manufacturable design incorporating preferably all the known elements from traditional in-line skates.